Removed one obsolete comment in ivas_stat_rend.h

• Related issues: #714 (closed)
• Requested reviewers: @vaclav

Reason why this change is needed

An incorrect comment may be misleading to the implementers of IVAS.

Description of the change

An obsolete comment in ivas_stat_rend.h, indicating that filter buffers may be preallocated. This has been resolved by setting a maximum length of the filters when loaded.

Affected operating points

Operation not affected, all BE.

Related to #714 (closed)